JP2006171753A - Microlens array sheet using micro machining and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microlens array sheet and a method for manufacturing the same, wherein no optical loss is generated when the microlens array sheet is manufactured by a conventional process, whereby an improved optical efficiency can be accomplished and a viewing field angle of microlenses can be controlled. <P>SOLUTION: The microlens array sheet comprises a microlens array having a convex and concave surface including curved portions and boundary grooves formed between respective neighboring microlenses via laser micro machining, and a void filler layer stacked on the microlens array. The microlens array sheet can be manufactured with a reduced number of process steps using laser micro machining, whereby improved productivity as compared to a conventional sequential semiconductor process can be accomplished. Using the laser micro machining, also, enables the manufacture of a desired three-dimensional micro shape. Therefore, the microlens array sheet is applicable as an optical sheet of a display system requiring a delicate surface shape. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a microlens array sheet manufactured using a microfabrication technique and a manufacturing method thereof.

  Laser micromachining technology has attracted a lot of interest because it has the advantage of making complex three-dimensional structures relatively easier than using existing semiconductor processing technology and relatively simple equipment. It is. In addition, the laser processing technique has an advantage that it can process not only semiconductor materials but also various materials such as ceramics, metals, and polymers.

  As a typical example of a manufacturing technique of a three-dimensional structure using a laser, a vapor deposition process in which vapor deposition is locally induced at the position of a laser beam to form the three-dimensional structure. An etching process in which only a region irradiated with a laser beam in an etching solution or gas is etched and etched gradually, or a photopolymer is irradiated with a laser beam and exposed to light. There is an optical modeling method in which only the polymer solution is cured.

  The shape of 3D structures that can be manufactured by laser micromachining technology is mainly a combination of linear and curved structures, so precise linear translation and rotation are required for accurate processing. ) Transport is essential. In the case of linear transfer, it is possible to ensure repeated precision up to 0.1 mm, and in rotary transfer, an angular resolution of 50 mrad can be obtained.

  In general, semiconductor elements, optical elements, liquid crystal display elements, micro electromechanical (MEMS) elements, and the like are manufactured by a semiconductor integrated process. The integrated semiconductor process is performed by repeatedly performing an etching process for selectively removing an exposed area after a photographic process using a mask or a reticle on which a predetermined pattern is formed. As described above, since the semiconductor integrated process must use a mask or a reticle having a fixed pattern, it must be newly manufactured as the pattern changes. Accordingly, it is inevitable to add production cost and production time. In addition, when an element having a short development time and a short product life cycle is manufactured using an integrated semiconductor process, there is a problem that it is difficult to increase the cost and quickly respond to a new product due to the above factors. Furthermore, the production of a pattern using an exposure process has a disadvantage that it is difficult to make a pattern finer below a certain level due to the limitation of the light source.

  However, with the recent development of laser micromachining technology, it has become possible to process complex three-dimensional fine shapes. The merit of laser microfabrication technology is that a three-dimensional fine shape can be manufactured in a single process, masks and reticles are not required, and a laser with a relatively short wavelength compared to a semiconductor exposure apparatus is used. Therefore, it is possible to cope with fine patterns. In particular, it has become possible to form a fine pattern in a large area through high precision of a laser control device for optimizing the beam profile and a stage drive unit for improving the quality of the formation pattern.

  However, due to the characteristics of the laser processing method, the boundary area of the pattern produced by laser micromachining cannot obtain a 90 ° C vertical shape, and when applied to the light sheet of a display system, the boundary area of the pattern is It acts as a factor that causes loss.

  An object of the present invention is an invention devised to solve the problems of the prior art as described above, and improves the light efficiency by improving the light loss phenomenon that occurs in the manufacturing process of the microlens array sheet. Another object of the present invention is to provide a microlens array sheet that can control the viewing angle of the microlens and a manufacturing method thereof.

  In order to achieve the above object, the present invention provides a microlens array sheet, which is a concave-convex microlens array including a curved surface having a boundary groove between adjacent lenses, and is laminated on the microlens array. Including a gap-filling film.

  In the present invention, the microlens forming the microlens array is preferably formed of one lens selected from a lenticular lens, a polygonal lens including a honeycomb lens, and a circular or elliptical lens.

  In the present invention, the microlens forming the microlens array is preferably an organic substance or an inorganic substance that transmits light.

  In the present invention, it is preferable that the microlens forming the microlens array has the viewing angle of the microlens adjusted by adjusting the height of the boundary groove.

  The present invention relates to a method of manufacturing a microlens array sheet using a microfabrication technique, and a) an uneven microlens array including a curved surface having a boundary groove between adjacent lenses using a laser micromachining technique And b) forming a gap filling film on the microlens array, and a method of manufacturing a microlens array sheet using a microfabrication technique.

  In the present invention, the method for forming the gap filling film in the step b) uses electrolytic plating, electroless plating, sputtering, sublimation vapor deposition, chemical vapor deposition, spin coating or spray coating. Is preferred.

  As described above, according to the present invention, by using a laser micromachining technique compared to a method manufactured by a conventional integrated semiconductor process, process steps can be reduced and productivity can be improved. Therefore, it is possible to manufacture a microlens sheet having a three-dimensional fine shape desired by the optical system, so that it can be applied to an optical sheet of a display system that requires a precise surface shape.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be noted that the reference numerals given to the following constituent elements and the like are given to the same constituent elements as much as possible even when they are displayed in other drawings, and it is judged that the gist of the present invention is confused. Detailed descriptions of known techniques and configurations will be omitted.

  FIG. 2 is a cross-sectional view of a microlens array sheet using a microfabrication technique according to an embodiment of the present invention.

  In the embodiment, the microlens array sheet includes the microlens array 1 and the gap filling film 4.

  FIG. 2 of the above embodiment schematically shows a method of forming the boundary groove 3 in the microlens array 1.

  Referring to FIG. 2, in order to minimize the optical loss in the microlens boundary region, which is a shortcoming of laser microfabrication, a boundary groove 3 is provided at the stage of laser microfabrication of the microlens array, and a gap filling film 4 is formed. In addition, the light efficiency is maximized.

  Between the adjacent lenses formed on the upper portion of the microlens array 1, an uneven shape including a curved surface is manufactured by laser micromachining.

  The microlens is preferably formed of a plano-convex lens. The microlens has a shape in which the horizontal and vertical curvatures are different so that the light emission angle can be controlled according to the direction, and the arrangement of the microlens includes a honeycomb shape and a hexagonal shape. It is effective to have a hexagonal shape, a diamond-shaped rhombus, a rectangular shape, or a triangular shape. Further, there is almost no space between adjacent microlenses arranged on the substrate, that is, the gap filling rate is close to 100%, so that the light efficiency can be maximized. In the present invention, after forming the gap between the microlens and the adjacent microlens using the laser microfabrication technique, it is possible to further add a gap filling film to make the gap filling rate 100%. Meanwhile, the arrangement of the microlenses formed on the substrate may be configured such that the peripheral edges of adjacent microlenses overlap each other. At this time, it is preferable that the cut surface of the boundary surface of the microlens configured so that the peripheral edges overlap each other is formed to have an arbitrary curvature. Furthermore, the cross-sectional shape of the microlens that determines the optical characteristics can be spherical or aspherical depending on the application.

  The light exit angle range of the microlens is preferably formed such that the horizontal axis is 30 degrees or more on the horizontal axis and the vertical emission angle is 10 degrees or more on the vertical axis with respect to the normal of the lens plane. The light emission angle is an angle at which half is obtained with reference to the front gain value.

  In addition, it is effective that the substrate serving as a support necessary for lens molding is formed of a polymer material, and it is preferable to use PET or the like as the material. It is preferable to use a resin that forms the microlens array and a supporting sheet material that has a high transmittance and a refractive index of 1.5 or more.

  The microlens is a planar convex lens in which unit microlenses having an elliptical shape, a hexagonal shape, or a rectangular shape are two-dimensionally arranged, and may be a spherical or aspherical shape microlens. Adjacent unit microlenses are arranged at a pitch of about 150 μm or less. The size of the pitch is preferably designed in consideration of prevention of moire.

  In addition, the microlens is formed such that the vertical and horizontal curvatures of the lens are different in order to adjust the light emission angle, and the curvature of the microlens is different from that of the microlens as described above. It is determined by the microlens height (sag) including the length and the respective aspherical constants.

  A gap filling film 4 is formed on the microlens array 1.

  The gap filling film 4 can be formed by a general thin film forming method, but can be formed by electrolytic plating or electroless plating, and can be formed by sputtering or sublimation vapor deposition. It can also be formed by chemical vapor deposition, spin coating or spray coating.

  The manufacturing method of the microlens array sheet as described above can be used as a manufacturing method for mass production, and can also be used as a manufacturing method for forming an original plate for mass production. Since the structure of the original microlens array sheet manufactured through the above method can be used as a mold for manufacturing a master, it can be used as a master for replicating the mold. In addition, a microlens array sheet replica having a similar structure can be produced in large quantities using techniques such as injection.

  FIG. 3 is a manufacturing step diagram of a microlens array sheet according to an embodiment of the present invention.

  Referring to FIG. 3, the microlens manufacturing step includes a step of manufacturing a concave / convex microlens array including a curved surface having a boundary groove between adjacent lenses (S301), and filling the gap above the microlens array. Forming a film (S302). Since the respective steps are the same as described above, detailed description thereof is omitted.

  The preferred embodiments of the present invention have been described above with reference to the drawings. However, those skilled in the art will be able to use various embodiments within the scope of the spirit and gist of the present invention described in the appended claims. Needless to say, modifications and changes are possible.

It is sectional drawing of the conventional microlens array sheet. It is sectional drawing of the micro lens array sheet by one Embodiment of this invention. It is a manufacturing step figure of the micro lens array sheet by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Micro lens array, 2 ... Micro lens boundary, 3 ... Boundary groove, 4 ... Gap filling film

Claims (16)

  A microlens array sheet using a microfabrication technique including an uneven microlens array including a curved surface having a boundary groove between adjacent lenses and a gap filling film laminated on the microlens array.   The microlens forming the microlens array is formed by one type of lens selected from a lenticular lens, a polygonal lens including a honeycomb-shaped lens, and a circular or elliptical lens. The microlens array sheet according to claim 1 used.   The microlens array sheet according to claim 1, wherein the microlens forming the microlens array is a plano-convex lens.   The microlens array sheet according to claim 1, wherein the microlens forming the microlens array uses a microfabrication technique in which horizontal and vertical curvatures are different.   2. The microlens array sheet according to claim 1, wherein the gap between the adjacent microlenses forming the microlens array has a gap filling rate close to 100%.   The microlens array sheet according to claim 1, wherein peripheral edges of adjacent microlenses forming the microlens array overlap each other.   2. The microlens array sheet according to claim 1, wherein a cut surface of a boundary surface between adjacent microlenses forming the microlens array is a spherical surface or an aspherical surface.   The range of the light emission angle of the microlens forming the microlens array is such that the left and right emission angles are 30 degrees or more on the horizontal axis with respect to the normal of the lens plane. The microlens array sheet according to 1.   The range of the light emission angle of the microlens forming the microlens array is a fine processing technique characterized in that the vertical emission angle is 10 degrees or more in the vertical axis with respect to the normal of the lens plane. The microlens array sheet according to 1.   The microlens array sheet according to claim 1, wherein the microlenses constituting the microlens array are arranged at a pitch of 150 μm or less. a) producing an uneven microlens array including a curved surface having a boundary groove between adjacent lenses;
b) A method of manufacturing a microlens array sheet using a microfabrication technique including a step of forming a gap filling film on the microlens array.   12. The method of manufacturing a microlens array sheet using the microfabrication technique according to claim 11, wherein the gap filling film in the step b) is formed using an electrolytic plating method or an electroless plating method.   12. The method of manufacturing a microlens array sheet using the microfabrication technique according to claim 11, wherein the gap filling film in the step b) is formed by sputtering or sublimation deposition.   12. The method of manufacturing a microlens array sheet using a microfabrication technique according to claim 11, wherein the gap filling film in the step b) is formed by chemical vapor deposition.   12. The method of manufacturing a microlens array sheet using a microfabrication technique according to claim 11, wherein the method of forming the gap filling film in step b) uses spin coating or spray coating.   Using micro-machining technology, including a microlens array having a concave and convex shape including a curved surface having a boundary groove between adjacent lenses using a laser micro-machining technology, and a gap filling film laminated on top of the micro structure array Mold for duplicating the microlens array sheet.

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